C180 engine inspection

[m111]

So, my engine has exactly 311113 km

Never had any breakdown, but engine is in kinda bad shape outside.

There is oil on spark plug holes and on the sides of engine. I need to change valve cover and 4 o-rings for each spark plug.
It needs a new catalytic converter, and some welding jobs.
It's misfireing on idle and sometimes when going downhill,
(This is related to oil leak,and cables. I won't change spark plugs till leak problem is solved.)
My engine wiring harness is in bad condition, cable insulation is falling from wires here and there.

I would like to ask some questions:

Does anyone had similar symptoms with oil leak past o-rings?
Why does some M111 engines have yellow stains on valve cover?
Why does it have oil in intake manifold??This is what I worry about
Does it means bad cylinder rings or something?

And last one: I want to rebuild engine wiring harness.
What part of harness should I rebuild and what size of wire to use?

 

[mbenz1]

Im also keen to find out why the engine covers have yellow / green stains on them.... Im sure some technical advice from our technical experts will be here sooon...

 

[miro]

Sounds like a generic renewal of camshaft cover seals and breathing hose renewal. Add to that some renewal of vacuum lines and intake and exhaust gaskets.

Be aware that breather goes to brass inlets on cylinder 2 and 3. These clog and oil then lurks in intake manifold.

All of the rubber and clear hoses harden up and crack. During renewal a plastic t-piece cracks also because it's so brittle that touching it makes it fall apart.

Renewal is relatively simple. It may include removal of the fuel rail so buy some new rubber seals for the injectors and fuel rail connection.

Basically you are just replacing all of the rubber pieces, two brass pieces and some vacuum tube.

 

[m111]

Is there any way to block oil to go in intake manifold, like installing catch can and small air filter on breather hose or something?
That should decrease oil consumption, because oil turns to vapor when it's hot and it goes to intake, when it cools down it turns to liquid state again, right?

Vacuum hoses are (still) ok, will check them out for few days..

 

[kth286]

connect a vacuum gauge to inlet vacuum hose and do tests as per instructions on package. They are cheap.

 

[markjay]

Is there any way to block oil to go in intake manifold, like installing catch can and small air filter on breather hose or something?
That should decrease oil consumption, because oil turns to vapor when it's hot and it goes to intake, when it cools down it turns to liquid state again, right?

Vacuum hoses are (still) ok, will check them out for few days..

Take care if disconnecting the breather hose from the intake manifold.

The breather hose does not only blow out oil fumes but also sucks in air at times - so you want to route it into a canister to catch the oil droplets and also put a small wet (K&N style) air filter on the hose to prevent dust being sucked-in.

...or just leave it as is and just let the engine burn off the oil fumes as the designers intended

With regards leak, not familiar with your particular engine but yes a common generic issue is blocked upper breather hose and/or crankcase ventilation causing the camshaft cover (aka rocker cover) seal to break and leak oil onto the spark plugs. As said the solution is to renew the camshaft cover seal and clear the breather hoses and crankcase ventilation system.

An air compressor will come in handy when cleaning the breather pipes while they are off the engine, or just buy new ones depending on their condition.

This issue can me mitigated to some extent by frequent oil changes and use of correct-spec oil to minimise the accomulation of sludge. And regular cleaning of the breathing system will prevent the camshaft housing cover seal from leaking again.

 

[markjay]

By the way... I did the canister and K&N mod on a 1.8L OHC Vauxhall engine due to the fact that the dual Weber conversion meant losing the breather connection point on the intake manifold, and the camshaft cover seal renewal and breather system cleaning on a 2.6L Vauxhall V6 engine because I neglected the routine cleaning at 40k...

 

[m111]

I've thinking exactly the same with "KN like"filter and catch can
http://avtoustam.az/wp-content/uploads/2011/08/m111.920.jpg here is engine pic, exactly same as mine. Look at the hose, it goes to intake pipe, not directly to manifold.

I think that oil consumtion should be lower, when oil catch can fills up, I will pour it in engine again

Also, I will get an K&N filter (part no. 33-2703), just because it doesn't need replacement every xxxx miles..

 

[markjay]

The oil collection canister will be open to contamination from water (road spray) and dust, I would not pour it back into the engine, unless you were joking....

 

[m111]

I heard this somewhere before, but I would not to do that.

But why is there oil vapor after all, is it normal for my mileage, and does that mean bad compression, worn engine parts or something?